The Burpee Seed thread kind of got off track so let's discuss it here instead.

It appears that some folks are confused regarding what comprises each of these catagories, especially when it comes to seed selection. I will however state again that a home gardener cannot buy GMO seed, even if they wanted to... only very large producers that are under contract & tight control. Anyone that states otherwise is either misinformed or intentionally misleading for ulterior motives.

So lets open this & talk about what 'type' of seeds are available to us & then discuss GM in a little bit... Basically, there are only 2 types of seeds available to consumers, heirlooms & hybrids:

Heirloom plants or seeds refer to any type of seed that has been grown for a number of years (since 1940 or before seems to be the general rule) & passed down from gardener to gardener. Heirloom plants are 'open pollinated', which means the plants are pollinated without human intervention, so by wind or insect pollination. Plants grown from heirloom seeds may not be as predictable as hybrid plants, but many gardeners prefer them for their flavor. Many also appreciate the idea of preserving the vegetable’s heritage.

Hybrid plants are created when breeders cross-pollinate different plants in order to maximize their best features, such as yield, size, resistance to disease & taste. Seed saved from hybrid plants isn't likely to produce a new generation with the same qualities. Instead, the second generation may look something more like one of the parent plants used to create the hybrid. Hybrids tend to be reliable & will produce uniform produce – and a lot of it, generally – but you may lose out on flavor. You will have to shell out money next year to buy new seed.

And, there is also some confusion about the definitions of "heirloom" and "open-pollinated." My understanding is that an heirloom is an open-pollinated variety that has been saved and passed along for many years (although I don't think there's an official cut-off for the time), while open-pollinated varieties are any that will come back from seed and be the same as the parent plant over successive generations. Assuming, of course, that they haven't been allowed to cross pollinate with another variety, either a hybrid or OP type. It is also possible to grow out seeds of a hybrid over the course of multiple generations, selecting for the desired traits, and eventually obtain a stable OP variety.

And all of this is further confused by the fact that a number of the seed catalogs are offering somethiing called "Heirloom Marriage Hybrid Tomatoes." Meaning, presumably, that heirloom varieties have been crossed to obtain a new hybrid.

If you choose to save seeds from your plants, there is the potential for cross-pollination from other plants of the same species, whether they are in your garden or growing nearby. As an example, if you are saving carrot seed, your garden carrots could be cross-pollinated by the weed/wildflower Queen Anne's Lace. If you are saving seed from your pumpkins, and your next-door neighbor is growing pumpkins or a squash of the same species, bees could be carrying pollen from one garden to another. And if you are growing corn and happen to live near a farm that grows Roundup-Ready GMO corn, your corn could be cross pollinated by the GMO pollen and therefore produce seed that has the Roundup-Ready trait.

Weedwhacker said:And all of this is further confused by the fact that a number of the seed catalogs are offering somethiing called "Heirloom Marriage Hybrid Tomatoes." Meaning, presumably, that heirloom varieties have been crossed to obtain a new hybrid.

I got a kick out of that too!!! I picture the marketing department all sitting around drinking beer after work, bouncing catchy phrases to best describe a basically simple hybrid, LOL!!!

I would also like to add to your pumpkin/squash example... add cucumbers, cantaloupe & watermelons to that list as well. All are cucurbits & will cross-pollinate.

Another area of confusion seems to lie with peppers... many times I have had someone say that their hot peppers and bell peppers crossed and the bell peppers were hot.

Cross pollination will only affect the seeds; so if your bell peppers seem to be "hot," the chances are that the seeds that they grew from came from peppers that had been cross pollinated with hot peppers.

Quoting from the article:
"Plants with favourable characteristics have been produced for thousands of years by conventional breeding methods. Desirable traits are selected, combined and propagated by repeated sexual crossings over numerous generations. This is a long process, taking up to 15 years to produce new varieties.1 Genetic engineering not only allows this process to be dramatically accelerated in a highly targeted manner by introducing a small number of genes, it can also overcome the barrier of sexual incompatibility between plant species and vastly increase the size of the available gene pool."

1.
When a commercial seed catalog calls a variety "OP", they mean that it was inbred over enough generations, with careful selection and rouging out undesirable plants to make the important traits breed true (homozygous). You can collect seeds from them and expect those seeds to come true - as long as you did not let them cross-pollinate with a different variety of the same species.

2.
When a seed trader marks a packet "OP", that might mean the same as the above definition of an OP variety, or it might mean something totally different: openly pollinated. "Openly pollinated" means that they were freely pollinated "by nature" instead of by human intervention. (She did NOT bag the blooms and pollinate them manually.) It means they were pollinated by the wind and insects, not by human intervention.

- They might have observed isolation distances.
- They might have inter-planted other varieties (promiscuous cross-pollination).
- They might have let an F1 hybrid go to seed with or without cross-pollination

Let me get back to you with some lengthy ramblings about GE techniques. Basically, directly manipulating genomes in labs with r4cently-developed techniques, not just hybridizing and selecting in fields.

Traditional plant breeding involves finding varieties with traits they want to add to some other variety. Sometimes they search for wild 'ancestral' varieties or just wild cousins. They control which plants pollinate other plants, then select for descendants that are closer to what they want. Every cross that gave them one gene they DID want brought in 50% of genes that you probably do NOT want. So they had to back-cross and select for years to get a possible improvement.

Today they may use DNA sequencing to make better guesses about which wild genes may be helpful, but that isn't called genetic engineering as long as the genes are combined only through one plant pollinating another, and saving seed.

For decades, plant biologists wished they had a better way to manipulate plant genomes. They knew how to "transform" bacteria, but not plants. Eventually they stumbled onto ballistics, which is VERY inefficient and clumsy. But better than nothing.

The earliest "gene guns" were modified Crossman air pistols! I've read that researchers had been trying for years and found no good way to "transform" plant cells. Then (I speculate), some lab assistant probably brought in his pellet gun and they had a good laugh but tried it anyway. Then they found that it worked better than the other methods.

They have fancier gene guns now - involving powdered tungsten. I heard that is still sometimes used to blast genes into 4-cell embryos in animal GE research.

One downside is inefficiency - even if a fragment of the DNA you want happens to be blasted into a nucleus, that DNA usually just sat there until it degraded. There was no mechanism to encourage it to cross over into the plants' chromosomes.

Another downside is randomness. Even in the rare case where the DNA winds up near a chromosome AND crosses into it, the location of insertion is random. Existing mechanisms that would normally control the expression of the gene (initiators, promoters and what-not) won't exist, so you have to try to inject an entire DNA sequence with the gene(s) you want plus the regions for initiating and promoting or regulating transcription.

Another downside is crudeness: since you're just shotgunning DNA into random locations in random chromosomes, you need to try to inject entire gene complexes. Biolistics (and the next method) are so crude that the only practical approach is to take DNA from any species, genus or kingdom that might have a desired effect. This "foreign" DNA is called "transgenic" if it came from a species that could not naturally have crossed with the target plant in nature (not the same species).

Up until the last few years, this "plasmid" method is what was meant by "genetic engineering" of crops.

It is as random as "biolistics" but more efficient. You can infect a Petri dish full of plant cells, and get lots of transformed cells, whereas shooting it with a pellet gun or accelerated tungsten powder works about as often as you might expect. Researchers using Agrobacterium plasmids still seem to use a lot of transgenic DNA to get results.

Agrobacterium species have some efficient mechanism for inserting DNA INTO plant cell DNA. In nature, this causes small galls or warts or tumors.

Molecular biologists identified the plasmids that do that (like a zipper that can unzip itself and then re-zip so that it is merged INTO the plant chromosome). The genetic engineering trick is to add the foreign or transgenic DNA to a plasmid and then let the plasmid infect plant cells (it is good at that).

Typically the plasmid, initiator and promoter regions of DNA are selected from digital libraries of DNA sequences other researchers have found helpful. There are also libraries of plant genes and gene sequences, but people still look at wild relatives, distant relatives, different species, genuses (genera) and Kingdoms to find DNA worth all the time and expense of plasmid transformation and then selection. It's faster and more efficient than "biolistics", but still random and clunky.

Sadly, the magic-zipper plasmid is carried along with the transgenes and other wanted sequences are present in every cell of every GM crop. So their presence in the environment has been multiplied by something like a billion-fold or trillion-fold.

(Also, each plasmid and transgenic DNA region in every cell in every GE plant is likely to have some "leftover" or "unwanted" DNA sequences that happened to come "along for the ride" when someone extracted a trans-gene from any source whatsoever (plant, animal, fish, fowl, bacteria, fungus, virus or purely synthetic). Researchers spend time and money to get functional DNA sequences, but how much time and money do they "waste" to trim off DNA that has no known function before adding them to a digital library? And when a team trying to alter a crop takes "Bacterial initiator XYZ" from a library, does he spend time and money "tidying it up" even BEFORE using it to try to improve a crop plant?)

I think this is what bothers people who consider GE an ecological hazard: Agrobacterium plasmids and other transgenic DNA are jammed into plants that never evolved them. Then we multiply that invented genome billions of times in fields of monocrops. "Horizontal transfer" of transgenic DNA is encouraged.

Chronologically, many DNA techniques were perfected in bacteria: power tools including sequencing, cutting, recombinant DNA methods and polymerase chain reaction. Those tools let researchers whittle, insert and copy-paste DNA, then save the result in a digital library from which the sequences can be re-created or edited further. All these genetic engineering techniques are used on DNA before injecting it into plant cells using the "shotgun" methods "biolistics" and Agrobacterium plasmids.

The newer techniques (Talens and CRISPR, say 2013) EDIT the DNA in the plant in a precise way in a predetermined spot. That is their advantage. Like editing one word in a book instead of trying to use a shotgun to blast a corrected page or chapter "somewhere" into the book.

If you see a version of a gene that you want to test, from a related variety or wild cousin, you can specify the exact DNA nucleotides that you want to change (by sequencing the plant, which is now easy and pretty cheap). Then you build your CRISPR sequence to identify THAT EXACT sequence of DNA within THAT SPECIFIC gene, and then edit only the nucleotides that you WANT to edit.

No need to add foreign initiators and promoters or regulators - you just let the plant continue using the regulatory regions that the plant already had wrapped around that gene sequence.

No need to import entire foreign gene SEQUENCES: the plant already has that sequence in place and you can just edit it.

The old ways (biolistics AND the Agrobacterium plasmid) were like shotguns: they added huge chunks of new DNA randomly, wherever it happened to attach to a chromosome. And usually parts of those new gene sequences were transgenic, which seems to be the main thing that many people consider ecologically risky.

Thanks very much! I hope others who know the information better will correct me and offer other perspectives.

(I forgot to mention: CRISPR works fine on humans and other animals. That's very good news for people with genetic diseases, though getting the edits into our gametes is much harder than editing DNA in body cells. I don;t think there is any standard way (yet) to repair a mutation so that the corrected genes are passed on to your children.

And the CRISPR toolkits are surprisingly cheap, and advertised online. That does raise issues of medical ethics! (Do we have an "understatement" smiley?)

I was in a heated GMO thread in DG for some months, and did some research when some very-pro-GMO people tried to blur the distinction between traditional plant breeding and modern transgenic genetic engineering.

Interestingly, some of the same people tried to blur the distinction between human-caused climate change and "weather varies form year year" and "we have Ice Ages and interglacials all the time, what's the big deal".

In one case, they wanted to Trust The GMO Scientists because it let agribusiness increase profits (and create crops that were more efficient, at least for some years or decades). Int he other case, "97% of Climate 'Scientists' Are Just Government-Sponsored Liars" because limiting CO2 emissions is bound to cut into profits.

We are getting close to politics now. I did notice a very strong correlation between political party or "Conservative/Liberal) and opinions about climate change and GMOs.

To be fair, almost everyone believes scientific evidence that supports their pre-existing passionate beliefs.

Many people find fault with "alleged scientists" and "paid-for, biased, so-called studies" who dare to report observations that contradict their pre-existing passionate beliefs.

I made myself follow up many popular articles about GMOs. Many or perhaps even most anti-GMO popular articles had headlines as bad as "Scientific Study shows GMOs cause leukemia" ... but the studies they cited said no such thing. I found a nearly 100% correlation of very alarming but vague claims with what I thought could only be deliberate, reprehensible misrepresentation ... "liar liar pants on fire".

On the other hand, "proof of safety", if defined as "show me lots of 70-year studies of humans eating lots of "GMO foods" in carefully controlled studies of humans eating "organic" food" obviously don't exist.

And some studies that were clearly pro-GMO in prior bias and conclusions skated quickly over spots that should have been acknowledged as limitations of the method.

I recall that the best study I saw, an expensive and difficult SIX-MONTH study of feeding pigs in a commercial piggery either one batch of feed from a GMO crop, or feed that was carefully traced to be from a somewhat similar but non-GMO crop.

Those who already knew that Frankenfood GMOs 'r gonna kill ya said the report proved horrible and deadly things. That might have been the headline that said "GMOS CAUSE LEUKEMIA!!!!!!!", because some white blood cells (leukocytes) were seen with unusual appearance.

On the other hand, those who were and always will be pro-GMO noted that the authors had to resort to new and detailed tests that they developed themselves (and were promoting) to even see any irregularities at the cellular level, and detailed autopsies that are never done in any normal food-testing study to find some stomach irritation and enlarged uteruses (uteri?)

So the same study was used by partisans to conclude "GMOS CAUSE LEUKEMIA!!!!!!!" and "the most detailed studies anyone can afford found NO HARM and almost no detectable difference in feeding pigs GMOs for their entire lifetime, even inventing brand new tests in order to scrutinize the crops more rigorously than synthetic food dyes or preservatives.

I thought it was funny and maybe relevant that the GMO feed tested as having a little aflatoxin and some other fungal toxin. Maybe it was poor storage, maybe a fluke, maybe irrelevant. Or maybe the moldy contamination caused the stomach irritation and enlarged uteri.

Hilariously, the authors dismissed the presence of aflatoxins and other fungal toxins in the GMO feed as relevant to their study "since it was less than the federal standard for toxins in animal feed". I doubt that standard is much better than "this much aflatoxing won't make the pigs so sick that they will poison humans", yet it was diosmissed as irrelevant to a study that tried to discern differences 100 times more subtle!

To be fair to the researches, everything else they did was scrupulously and very rigorously fair - they controlled for everything up to and including weather, bedding and the phase of the moon. Probably they re-checked the feed at the end of the six month study and found the common levels of toxins in GMO feed but not the other feed ... what were they going to do, ask for all that money and time again to repeat the study? Or publish?

I read the original long-term pig-feding journal article, and I was impressed by the authors' statement that they looked closer and developed new techniques for looking for smaller changes, than were done in any normal feeding study or autopsy.

"Researchers said there were no differences seen between pigs fed the GM and non-GM diets for feed intake, weight gain, mortality, and routine blood biochemistry measurements."

It would interesting to see what abnormalities their state-of-the-art enhanced scrutiny would find as a result of other dietary practices.

It was a great study in most ways, and presented very well and sounded honest and unbiased to me.

90% of the GM corn was a triple-stacked GE cultivar (two Bt genes and one RoundupReady mod.)

The soy was all RR RoundupReady .

The non-GM corn and soy were fairly close to the GM feeds, but not genetically near-identical varieties.

The piggery workers were somehow kept blind to which group of pigs were which (nice touch!), but still fed one set with GM feed and the other set with normal feed.

Too bad they didn't store the GE feed as mold-free as they stored the conventional feed! (That was my thought, anyway.) Their testing showed "allowable" amounts of highly toxic aflatoxin and some other mold toxin in the GE feeds (I THINK from Aspergillus flavus and Aspergillus parasiticus).

"2.08 ppb total aflatoxins and 3.0 ppm total fumonisins in a pooled sample of the GM feed and no aflatoxins and 1.2 ppm total fumonisins in a pooled sample of the non-GM feed. No other mycotoxins were detected. "

That "allowable" amount of mold toxins MIGHT have caused the changes they observed, or other mold products might have caused the inflamations and organ size changes (that's just my guess, not the authors'.)

Certainly the tests that established the "allowable" limits did not use the new tehcniques that these admirable researchers developed to put an extra-powerfull microscope on the effect of 100% GM fodder.

As I said at the time, the test actually supports "pro-GMO" activists more than "anti-GMO" activists. A really good long-term study feeding 100% GMO feeds found only changes so slight that usually no one would have noticed them!

As they said:

“The results indicate that it would be prudent for GM crops that are destined for human food and animal feed, including stacked GM crops, to undergo long-term animal feeding studies preferably before commercial planting, particularly for toxicological and reproductive effects.”

There certainly are tests that are required already before GMOs get licensed - I had assumed some of those were long-term feeding studies! I see that the Consumer's Union says: "There have been very few animal feeding studies of GE food to date, and extremely few that lasted longer than 90 days."

A 6-month feeding study certainly is a long one, but I agree there is value, expecially in trple-stacked GMOs, and ones with brand-new genetic additions, in doing expensive tests. Too bad the organic food industry isn't rich enough to fund studies like that ... or else even they expect the results to be flattering to GMO crops.

I guess it is arguable whether the long-term studies need to have NEW tests invented and performed that are more advanced and sensitive than any food product has ever been subjected to before.

Including tests that, when they come out positive, leave some people shrugging indifferently and others only mildly alarmed. (A few organs were enlarged by as much as 25% which they said WAS statistically signifigant with 168 newly-weaned pigs including controls).

I would love to know whether the stomach inflamation was related to Bt, the RuR gene, aflatoxin or poor feed storage. "More studies are desirable ..."

Of course, the best long-term feeding study is that almost all farm animals have been eating a high % of GM crops for 15 years. I guess little or no damage is discernible, or we would see studies proving it was.

Or maybe there is damage too subtle to see through the haze of unsanitary conditions and overcrowding that constitute normal practice in commercial piggeries.